


Dean and Castiel's Lagoon of Love

by almaasi



Category: Supernatural
Genre: Bisexual Dean Winchester, Bottom Dean, Castiel (Supernatural) Has Tentacles, Cursed Castiel, Dean Winchester Loves Hentai, Dean's Tentacle Fetish, Explicit Consent, Fluff, Horny Dean Winchester, Human Castiel, Illustrated, M/M, Men of Letters Bunker, Octopus Castiel, One Shot, Porn With Plot, Porn with Feelings, Romance, Sexual Roleplay, Shadow work, Smut, Tentacle Sex, Tentacles, Top Castiel, Witch Curses, art does not contain any tentacles or porn
Language: English
Status: Completed
Published: 2019-04-06
Updated: 2019-04-06
Packaged: 2020-01-05 12:27:26
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 12,519
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18366011
Author URL: https://archiveofourown.org/users/almaasi/pseuds/almaasi
Summary: Castiel is presently an octopus from the waist down. But the curse is only going to last a few more hours, and there's only so long Dean can delay before asking Cas to act out the erotic anime closest to his heart: "Sweet Princess Asuka Meets the Tentacles of Pleasure". Cas is the tentacle monster. And Dean is the heartbroken princess, seeking renewal in the monster's lagoon of love. The storyline may not be complicated, but when their half-innocent roleplay becomes more sensual than they planned, their feelings grow complex. Dean can leave the paddling pool in the bunker garage behind, but once Cas has his legs back, he can follow. There are still feelings to resolve. Their story isn't over yet.





	Dean and Castiel's Lagoon of Love

**Author's Note:**

> This fic exists because you, my dear readers, voted in my survey last year, and tentacle kink (aka "consentacles") was a trope that a bunch of people requested. Took me a while, but I got there in the end.  
> Thanks also go to my Patrons, who voted on which fic idea to work on! The majority voted for [**Circuitry and Dust**](https://archiveofourown.org/works/18284159), which I posted last week, but a few others (and secretly myself) wanted me to give this a try too. Tentacles are not my thing. But I really wanted to find a way to MAKE them my thing for the purposes of this trope, so this is basically Tentacle Porn For People Who Don't Usually Enjoy Tentacle Porn. So if you're on the fence, you might like it. Just sayin'.
> 
> Beta'd by [Katie](https://crab-full-of-rocks.tumblr.com/) and [Joanjun](https://roisu10.tumblr.com/)!!

_It's possible there's a little monster in all of us._  
— Castiel (season 10, episode 10, “The Hunter Games”)

 

“See,” Dean said matter-of-factly, “ _this_ is why we don’t mess with witches.”

“The case centered around a coven of witches, Dean,” Castiel said tiredly, sitting on the edge of the Impala’s back seat, arms out, waiting for someone to pick him up. “Interacting with them was somewhat inevitable.” His breath clouded out in the morning air, half golden, half in the shade of the trees.

“Yeah, well,” Dean grunted, draping Castiel’s leathery tentacles over his left arm, grasping Castiel’s lower back with his right. He straightened up, eyes watering, legs shaking. His voice came out strained and breathy as he finished, “We should’ve gone with a diff— different case...”

He took huge, stomping steps towards the entrance of the bunker.

Sam watched all this warily, his hand on the bunker’s sigil-encrusted fire door. “Dean,” he said, “maybe we should go in via the garage.”

“Whah’re you tahhlkin’ ‘bout, this is fihhhne,” Dean whispered, his breath thin and his boots stuck on fallen leaves. “Tentacles aren’t heavy at all.”

Castiel held Dean around his neck, peering at him in concern. “There’s a vein on your forehead I haven’t seen in a while.”

“Hreeef,” Dean wheezed, legs buckling.

“Whoa, whoa—” Sam rushed up the concrete steps to grab Castiel’s torso, leaving Dean with eight dense limbs to hold.

“In case anyone was wondering,” Castiel said, facing the ground, Sam’s hands on his shoulders, while Dean held slowly-drying sea noodles that didn’t want to be held, and flinched occasionally, “this is a _lot_ of fun.”

Sam shot Dean an uncomfortable smile. “Garage.”

Dean grunted, and started back to the car, Castiel carried between them.

   


** ≋≋≋ **

  
 

There was a ten-foot-wide overground paddling pool folded up in the Men of Letters’ cathedral-esque garage, which Dean had purchased in the summer of last year. They used it once to swim – there was still a black swan-shaped pool float deflating upside-down on a tool bench – and then the pool was repurposed as a bath for some ritual or other, because Dean absolutely refused to use the tub inside for all that gross stuff.

Now Dean unfolded the sky-blue pool canvas and stretched out its corners in a square, while Sam arranged the scaffolding and began assembling it.

Castiel sat on the hood of the Impala, hands out behind him, chest bare, looking dejectedly at the pool. His eight indigo-blue tentacles hung limply off the hood, the ends slowly curling and uncurling. He felt crusty. And dry. And he didn’t like it.

“How long is this going to take?” he asked.

“However long it takes,” Dean said.

“Uhh, twenty minutes,” Sam said. “So long as we find the firehose.”

“Thank you, Sam,” Castiel muttered. “For a less frustrating answer.”

Dean grunted, kicking the pool edge into place, clipping two bits of frame together inside it. He turned his eyes to Castiel, looking at him, then at the alien appendages below. “So what are you, exactly,” he demanded. “A squid? An octopus?”

“I remain human,” Castiel said bluntly. “I just happen to have—”

“A deep-sea beastie on your lower half.”

“A problem,” Castiel finished, arms folded.

Dean started to grin. “Angelfish. Octo-Cas. Castipus? Tenta-Cas.”

“ _Castiel_ , thank you.”

Sam flopped part of the canvas in an arc, and the _clompff_ got their attention. “Would you two stop bickering? Dean— Pay attention!”

“What, like it’s _my_ fault?” Dean uttered, head down to help with the pool. “Cas goes and gets his taint turned into a second mouth, and you expect me not to stare?”

“Not at his second mouth, no,” Sam frowned. His eyes darted to Castiel. “But – really? Is that true?”

“Octopi do have a mouth on their undersides where the tentacles meet, yes,” Castiel said to Sam, while glaring at Dean.

“Gross,” Sam said, as delighted as a ten-year-old child.

“Tell him where your dick is now,” Dean grinned, eyes on the pool.

Castiel scratched the side of his neck awkwardly.

“It’s one of the tentacles, isn’t it?” Sam said. “Do you know which one?”

“Of course I know which one,” Castiel said quietly, eyes turned away.

“Now Cas has a huge, blue, wriggly dick,” Dean grinned, clipping the final pole into the pool’s outer frame. “All right! Where’s that firehose?”

“How do you lose a firehose?” Castiel uttered, squinting judgmentally. “It’s over there, attached to the reel on the wall.”

“So it is.”

Castiel rolled his eyes while Dean and Sam made their way over there. Dean rolled out the hose, aimed it into the giant blue trough, while Sam turned on the water. “Here it comes!” Sam called across the garage.

Dean laughed gleefully as the water gushed and gushed into the pool, the force of it moving the pool along a few feet. Dean aimed the hose up, water arcing across the room until he caught up with the pool, and the weight of the water already inside held it in place.

“Turn the flow down a bit!” Dean called over his shoulder.

Castiel pushed himself up on his hands, wanting to see inside the pool. Dean noticed his interest, and told him, “Couple inches full already. Hey, you need saltwater or is freshwater fine?”

“I— I don’t know,” Castiel admitted. “But my legs are... thirsty.”

Dean shot him a pitying look. “Must suck.”

“These do, yes,” Castiel said, lifting a tentacle to show the circular suckers on the darker underside. Dean laughed, and Castiel smiled, glad he got the joke.

As the minutes passed, and the _glooshshhuffhh_ slowly became a steady, deep-toned hissing, Dean nodded, and shouted to Sam, “All full! Turn it off!”

There came a squeaking of a large metal faucet, and the hissing ceased.

Dean gave the hose nozzle a good shake, letting more water spew in as Sam rolled up the other end like an almost-empty toothpaste tube. Dean left Sam to do that, and went to Castiel.

“You ready?” Dean offered his hands. When Castiel looked wary, Dean assured him, “You could piggy-back! Or, uh...”

His voice trailed off, as Castiel was already wrapping his arms around Dean’s neck, tentacles around his waist, face-to-face. “Just get me in the water,” he pleaded. “I’m dehydrating.”

“Okay,” Dean said, palms touching Castiel’s lower back, skin to skin. One hand lowered, curious about the join; Cas’ well-muscled frame faded to squishier octopus skin, and it felt like cool, buttery leather. With a grunt, Dean lifted Cas under where his butt should’ve been, and turned around, marching heavily across the smooth concrete towards the pool.

Castiel looked over his shoulder to watch the pool approach, but then turned to watch Dean. Dean felt his eyes on him. And then he noticed Cas close his eyes, fatigued, trusting, or both.

“Probably shouldn’t mention,” Dean said under his breath, “how your second mouth is right up on my crotch, huh.”

Castiel raised an eyebrow, smirking as he peeked out from under his lashes. “And _I_ probably shouldn’t mention,” he said, just as quiet, “how you have a partial erection.”

Dean wet his lips, heat in his cheeks. “Nn-nh.”

Castiel smiled slyly, eyes lowering, prepared to keep Dean’s secret. Dean pressed to the edge of the waist-high pool and leaned forward. Castiel gasped as his back touched water, and Dean saw the flash of joy in his eyes as he let Dean go and shot down into the blue, sloshing waves of liquid outside, washing a nearby motorbike in the process.

“Holy shit,” Dean laughed, hands on the pool rim, peering down in awe as Castiel swam around underwater, a tan blur followed by a blooming indigo flower, folding its petals tight, and blooming again a second later. Castiel swam three times around the pool, then burst up like the Little Mermaid, flaring water from his hair, arms up to push his bangs out of his eyes. He laughed raucously, eyes crinkled, and Dean laughed with him, sharing his delight. Sam laughed too, but more in astonishment than anything.

Castiel bobbed in the water, tentacles flaring and closing halfway, his skin glistening, his grin wild, his eyes dark and satisfied. “Thank you, Dean. Sam.” He sighed and lay back, stretching out his tentacles like legs, then relaxing. He floated, blissful.

“Well, okay!” Sam said proudly. “That’s that done. Pool seems to work.”

“Yeah.” Dean ran his hand over his lips. “Now we gotta figure out how to fix this.”

“You Google how to reverse animal curses, I’ll call Rowena,” Sam said, hands on his hips. “She’ll know. She’s probably gonna love this.”

“More witches,” Dean muttered disgracefully.

“I’d rather not be stuck like this forever, Dean,” Castiel advised, coming to hang on the side of the pool, elbow hooked over the edge. “I may be fine in water, and for a short time out of it, but I doubt these would be any use on hunts.” He gestured to the eight inky coils that swayed with the movement of the water.

“Hey, I dunno about that,” Dean supposed, arms crossed on the pool edge, legs stretched out behind him, wearing a playful grin. “Could strangle a few vampires. Ink ‘em right in the eyes. Or just freak people the fuck out.”

“You don’t seem scared,” Castiel said lowly, eyes locked to Dean’s. Dean could smell the water on him, eau du firehose.

Dean licked his lips, trying to hide his attraction, but knowing it was useless. “I watched enough anime porn to know that what all the tentacle monsters _really_ want is to get lucky.”

“Tentacle... monsters,” Castiel repeated.

“Mm.” Chin on his hand, Dean let his gaze drop lower, enjoying Castiel’s perked nipples, his happy trail, and the mysterious darkness under the water. “Hmmhh...”

“Dean, come _on_!” Sam called from the door to the bunker’s proper insides. “Quit flirting and help me fix him!”

“Flirting—! I’m not flir—” Dean spluttered, turning to Sam. “You disgust me, Sam. You really do.”

“That makes two of us.” Sam watched his brother approach, holding the door open for him. “Bye, Cas. See you later.”

“Bye,” Castiel said. The door closed, and he was left alone in fluorescent lighting, breathing the smell of plastic-coated-canvas and motor oil, but he sighed happily, leaning back and diving into an arc, swirling through the water in loop-de-loops.

   


** ≋≋≋ **

  
 

“Twenty-four hours,” Sam sighed in relief. “That’s all. It’s a temporary curse, Cas’ll be back to normal when the sun reaches the same part of the sky it was in when he got hit.”

Dean peered over his laptop screen, watching Sam put the phone down. “But the Earth is hurtling through the universe at God-knows what speed. Seasons change day by day. The sun’s never gonna be in exactly the same place.”

“Well, Rowena says it will be tomorrow. Cas got hit at, what,” Sam checked his watch, “two a.m? And it’s past twelve now. So he’s got another fourteen hours of tentacle time, and then he’ll be back to normal.”

“Two hairy legs and a pink, non-wiggly dick,” Dean said to himself.

Sam eyed him dubiously.

Dean noticed Sam’s eyes on him, flicked him a glance, then lowered his gaze and chin, then his laptop screen. “I’m gonna go tell him.”

“You do that,” Sam said, watching Dean skulk off.

   


** ≋≋≋ **

  
 

Dean headed up to his room first. He stood behind the closed door, hands over his face, groaning under his breath. He let out all the air from his lungs, and all the thoughts from his head, then parted his hands.

His eyes fell upon his memory-foam mattress, two pillows piled up on one side, the other side untouched and never slept in. Dean went to that side and sat down, hands hung between his parted thighs. He sighed again, ruffling one hand through his hair, trying to tease away invasive thoughts by combing them out.

But he couldn’t stop thinking about it. He’d be wasting a once-in-a-lifetime opportunity if he didn’t even _mention_ it to Cas, wouldn’t he? He could at least talk about it in a jokey sort of way.

Dean got up and faced the bed, lifting the mattress. His hand breezed past the gay porn and his thick, ribbed vibrator, and landed on a bright pink and orange cardboard sleeve, with the black rectangle of a VHS tape inside.

He lifted it out, holding it.

 _Sweet Princess Asuka Meets the Tentacles of Pleasure_ , said the heading in English, under a 1980s Japanese font. The art on the cover was a delicately realistic rendition of the animated scenes on the tape, with a long-haired, round-bosomed princess in the midst of orgasm, wearing only her beaded crown upon loops of black hair, the crown’s tassels flared with movement beside her ears. Behind her was a great tentacled beast, the point of penetration hidden behind the princess’ slim rear. It held her close with its black limbs, and although the water around them sprayed in all directions with the force of their movements, Dean liked to believe she was being held gently.

Dean stared for a while, lips parted and wet, eyes soft.

He gulped, turning the tape over to look at the back. He sighed longingly, seeing a screenshotted frame of the beast when he became human at the end. He looked a lot like Cas.

Dean bowed, ready to put the tape back under his mattress, where nobody else would ever see it.

But he only touched the tape to the mattress when he withdrew it again, looking at it a second time. He nibbled his lip, decided he was being ridiculous, and slipped the tape into the darkness, hidden, with all the other things he didn’t want to share. Not with Sam. And _definitely_ not with Cas.

   


** ≋≋≋ **

  
 

“Fourteen hours?” Castiel turned his head, pondering that. “That’s not too bad. If I keep my lower half in the water and my upper half out, I won’t get too pruny.”

Dean shifted in place beside the pool, rubbing the back of his neck. “Do you still need to pee and stuff?”

“I’d rather not discuss my bodily functions with you at this time, thank you,” Castiel said dryly.

“But—”

“But bring me dinner,” Castiel said. “Please. When you’ve made it.”

“Yes, sir,” Dean snarked, making Castiel roll his eyes. Dean lingered, leaning on the side of the pool, fingers trailing through the water’s surface. He gazed at the darkness below Castiel. Cas moved all the time, so the water moved all the time, but it was clear enough that Dean could just about make out the shape of each tentacle, stretching and curling.

“Do you usually stare at your friends while they’re naked?” Castiel asked.

Dean looked up. “What?”

“In case you hadn’t noticed, I am completely nude.”

Dean blushed. “Y-Yeah, well, it— It kind of. Doesn’t count, right. ‘Cause it’s tentacles, not legs.”

“But one of these is in fact my penis.”

Dean tried to look at Cas’ eyes and not anything else, but he was blushing too much and had to look away entirely, just for sanity’s sake. “Sorry, man,” he uttered, gulping. “Just—” He huffed, shaking his head. “Nah, uh. Didn’t mean to make you feel weird, or anything.”

“It’s a novelty, I understand,” Castiel said. “I, um. I permit you to look, just to satisfy your curiosity. If you really must.”

Dean pulled away, slowly walking backwards. “No, no, um. I’m good. Thanks. But.” He thumbed over his shoulder. “I gotta get— Y’know.”

“You have an erection again,” Castiel said, a wrinkle between his brows. He looked from Dean’s crotch to his face as Dean covered himself with a hand. “I believe this is the third time.”

“Third? When—?”

“When you first found me writhing on the ground, having been cursed,” Castiel said.

Dean breathed twice, caught between stepping closer to indulge himself, and running away to preserve whatever dignity he had left.

“Does this form arouse you?” Castiel asked, looking down at himself, then up at Dean.

“What? No,” Dean lied, while obviously lying. “What kind of crazy messed-up person would find—” He gestured to Castiel. His entire face, ears, and chest were burning. “Hhhot.”

Castiel narrowed his eyes, trying to figure Dean out.

Dean shut his eyes tight, one hand holding the hem of his plaid shirt in front of his crotch, the other pressed to his forehead in shame. He finally snapped, and stepped forward. “All right, look,” he said. “There’s this anime. Y’know, Japanese—”

“Japanese animation,” Castiel finished. “Yes, I know, Metatron informed me of more than just Western media when he stole my grace.”

“Right. Well. You ever—? Ever heard of one called _Sweet Princess Asuka Meets the Tentacles of Pleasure_?”

“Tentacles of... pleasure,” Castiel repeated, monotone.

“Uh-huh.” Dean put his hands in his pockets.

Castiel’s eyes skipped to the left, then right, as he thought, then pressed his lips together. “I haven’t heard of that, no. It’s strange. I know the titles and synopsis of all major media releases since the beginning of time.”

Dean shot a nervous glance towards the bunker’s door, praying Sam wasn’t out there. “Yeah, well, it’s kind of niche. And it’s, uh. Maybe my favourite.”

“Tentacles of pleasure,” Castiel said again, without enough tone for Dean to interpret his feelings on the phrase. “I don’t know the synopsis, but I imagine this Princess Asuka – namesake of a real princess from the year seven-hundred A.D, by the way – finds her way to being... in a relationship, with a, um, tentacle... monster.”

“That’s about the long and short of it, yeah,” Dean mumbled. “It’s a freaking classic, okay, don’t judge me.”

“I cast no judgement,” Castiel said ethereally, which made Dean scoff.

“Oh, sure, buddy, says the guy who complained I drive too slowly and _also_ that I cut corners when I can see what’s around the bend. You judge, Cas. You judge hard.”

“Not about this,” Castiel decided, resting his lower back against the pool’s edge, head turned so he could gaze at Dean coolly, like he really didn’t care. Dean couldn’t tell if he was faking for his sake. “So that’s why you’re excited. My current predicament reminds me of your favourite... art.”

“It _is_ art,” Dean agreed, happily. Cas actually _got_ it.

Castiel curled the tip of one tentacle, lifting it out of the water to look at it. Dean looked too, enthralled by its wet sheen. Tentacles looked so much sexier in real life. He could only imagine how fun they’d be to play with.

“Would you—” Dean fretted, sucking his lower lip, then freeing it. Heart pounding, he asked, “Would you wanna watch it?”

Castiel seemed surprised.

“Just for reference, you know,” Dean babbled, “so you know what I mean, and like, can appreciate the, uh, the artistry, and the, the, the animation, and the studies that would’ve happened before drawing tentacles, and—”

Castiel laughed, head down. “Dean,” he said, locking eyes with him, amused, “I have fourteen hours to kill, and I’m stuck in a ten-foot-square paddling pool in a garage. I will take whatever entertainment you have.”

   


** ≋≋≋ **

  
 

Once, after succeeding at a hunt at a high school, Dean had decided to reward himself by stealing a broken TV from the janitor’s closet. It was one of those two-foot black boxes with a sloping back, speakers that only mumbled no matter how loud the volume was set, and everything on the screen was made of no more than a hundred pixels. It lent itself only to 1990s documentaries with actors dressed up as Roman soldiers and Christopher Lee or David Attenborough doing the voiceover, or _Sesame Street_. There was no in between.

Dean also stole the wheely frame it came with.

One wheel squeaked as he rolled it into the garage, right up to the pool.

“It _kills_ me that they don’t make VHS players any more,” Dean said, patting the trusty old thing supporting the TV. “Thank God this baby’s tough as nails. Wouldn’t swap this for a whole Apple store.”

“Is that the movie you wanted me to see?” Castiel asked, swooshing closer to see Dean’s anime tape in its cardboard sleeve. He tilted his head. His eyes widened. “She, um. Princess Asuka. Seems very... naked.”

Dean looked at the cover. “Oh. Yeah. Ain’t she pretty?” He showed Castiel.

Castiel’s cheeks coloured, lips parting. “Is this pornography?”

“Pfff, no,” Dean chortled, pulling out the tape. “It’s _artistic_ nudity.”

“Of a sexual nature.”

“Well. Kind of.” Dean shrugged. “Erotic, maybe. It’s cool, you’ll like it. She’s a real badass, Cas, she rules a whole kingdom and she has this magic sword, right, and she’s an awesome fighter, but she’s scared of accepting help and all she really, really wants is to be _touched_ , and loved, and— Ahh, you know what, I’m spoiling it, I’ll just—” He pushed the tape into the player, watching it get eaten up in a black plastic clatter.

“ _aH! aH! AH! AH!_ ”

“Whoa, spoilers, spoilers,” Dean hit the rewind button and waved a hand in front of the screen worriedly. “Don’t look, Cas, it started right in the middle. Must’ve left it there last time I watched.”

“Dean, this is pornography.”

Dean huffed. “Yeah, but— But it’s not like that, it’s really different from other stuff.” He watched the screen as it flashed through black and pink, orange, then green as Princess Asuka walked backwards through the forest, back to her yellow castle, where her maids untold her about the magic pool in the forest where she could seek the answers to her kingdom’s problems.

“How is it different?” Castiel asked.

“Well, there’s an actual storyline, for one thing,” Dean said, rolling a shoulder, then bowing his head to fiddle with his plaid shirt sleeve, rolling it tighter. “And the monster gets consent before he touches her, which, honestly, is kind of rare in the tentacle monster genre.”

Castiel seemed wary.

Dean wet his lips. “Look, if you don’t wanna, that’s fine. I just. I dunno. I thought maybe you’d be into it. Maybe, uh, relate to the characters. I know I do. So.”

Castiel’s eyes shifted from the frozen-black, glitchy screen and over to Dean. “Am I the monster?”

Dean shrugged. “Might be. Sometimes I am. Mostly I’m the Princess.” He smiled shyly once that was out of him, and he grinned, avoiding Castiel’s eyes.

“Is that how you see me? A monster?”

Dean looked at Cas. “No. Naw, man, you’re—” He sighed. “Just watch, would you? You’re no more a monster than Monsutā is.”

Castiel sank down in his water, waiting for the movie to start.

Dean hit play, then went around the pool to lean on the other side, where he had a better view.

   


** ≋≋≋ **

  
 

“So!” Dean grinned, thumbing the button to rewind the tape now it had ended. “What’d you think? Ehh? Ehh?”

Castiel smiled a little, a soft shrug lifting his bare shoulder. “Better than I expected.”

“Right?! Told you.” Dean did a shoulder-shimmy happy dance as he held the rewind button. “Seriously, Cas, I know this was maybe not your thing, but – thanks for putting yourself through it, and all that.”

“I did enjoy it, Dean, I’m not just ‘saying that’.”

Dean grinned, catching his eyes. “I thought I’d be fast-forwarding half of it. Figured you’d complain at the sex scene, or something.” He pushed his lower lip into an appreciative arch, pleased Cas had given the sex scene his full attention, with nary a disparaging comment or a grunt of disgust.

“Do you have an erection now?” Castiel asked, coming to the side of the pool to look.

“Hey, eyes up here, buddy,” Dean uttered, pointing his fingers at his own eyes. “What my dick’s doing is none of your business.”

“I’m aroused,” Castiel said happily. “It’s very odd, having a tentacle penis.”

Dean coughed, almost dropping the tape as it clattered into his hand. “Okay. That’s great. Good for you, Cas.” He safely slipped the VHS into the sleeve, and put it by the TV, pushing the TV out of splashing distance.

He gulped, wondering what the hell they were meant to do now.

“Do you usually touch yourself while you watch this?” Castiel asked. “I wasn’t sure if I should.”

Dean blushed. “I did. A little. Not enough to, you know, finish. But a bit.”

Castiel looked down into the water. “Should I touch myself now?”

“You don’t have to, Cas,” Dean assured him. “Sometimes it’s nice just to get going. No pressure to do anything.”

“Right. Okay.” Castiel shifted awkwardly, avoiding Dean’s eyes as he swam to meet him at the edge. Castiel’s breath stuttered, then he asked, “Did you have any particular intention behind showing me that movie, or was that it?”

“No, that was it.” Dean shrugged. “Just so you know what’s up with me and the tentacles.”

Castiel smiled, and quickly his smile grew to a grin. “ _Join me in my lagoon of love, Princess,_ ” Castiel purred in Monsutā’s deep, rolling voice. “ _I sense how grrreatly you crave my touch._ ”

Dean giggled, backing away, loose-limbed and fluttery-hearted. “Stoh-hopp,” he complained, pressing back to the pool edge. “That’s weird, man, don’t do that.”

“ _Let me pleasure you the way you_ ache _for_ ,” Castiel went on, taking Dean’s bicep and groaning into his ear. “ _You’ll see that neither you nor I are monsters after all, Princess._ ”

Dean bit his lip, moaning as it slipped out from under his teeth, wet. “Shit, man.” His breath caught, head turning to face Castiel’s, eyes unable to rise. “You’re gonna fuck up our friendship real fast if you keep doin’ that voice, Cas.”

Castiel grinned. “I couldn’t resist.”

“Neither can I,” Dean breathed, desperately trying to calm his heart. He cleared his throat. “Look. You stay here. Do whatever you want with your tentacles. I’m gonna go cool off, take a cold shower.”

“Plenty of cold water here.”

Dean cackled, but shook his head, backing away. “Thirteen hours, right? And then this whole mess is cleared up.”

Castiel smiled after him, somewhat flatly. “Thirteen hours.”

Dean stood in the doorway, ready to leave. He nodded, and turned away. “We’ll make it.”

   


** ≋≋≋ **

  
 

They weren’t gonna make it.

Dean couldn’t fucking sleep. His erection had faded but it remained as an urge, wanting to pop up, craving a hand or a tentacle around it. Dean tossed and rolled and humped the bed but all he could think about was Cas easing a tender and slippery tentacle inside him. Dean whimpered, squeezing his legs together around a pillow.

He checked his clock again. Midnight.

He could barely believe they made it through the day. Dean spent most of it in the kitchen with an ice pack shoved down his pants, hands busy making casserole and pie and salad and burgers, then Winchester Surprise, and, as a last resort, cupcakes. Nothing could take his brain, or his smaller brain, off the beast in the garage: his best friend, merged half-and-half with his favourite sexual fantasy. It wasn’t fair. Why couldn’t he have just met a horny sentient octopus? Why did it have to be _Cas_?

Asking anyone else to play out the movie would’ve been easy.

Over the course of the day, Dean had accidentally decided what he wanted to do. He wanted to ask Cas to roleplay, and Dean would play Princess Asuka, and Cas would play Monsutā, and it didn’t even have to be sexy, they could skip all the sexy stuff, but _God_ , what a waste it would be not to do that too.

Part of Dean just wanted to mess around like kids did, acting out _Back to the Future_ according to the script, and having a good, innocent time.

But the other, deeply visceral part of Dean, wanted to have a blue tentacle dick stuffing itself in his ass. Dean squeezed the pillow again and whined, trying to resist humping. He didn’t want to jack off, because he’d only think of Cas and not Monsutā, and he already knew that when he thought about Cas, he came way too soon. Either he touched himself properly – _slowly_ – or he didn’t at all.

He looked at the clock again. Two minutes past midnight.

Sam had guesstimated that Cas got hit by the spell at two in the morning. But that was only approximate. Cas might have less than two hours before he was human again.

Dean sat bolt upright. “Fuck it,” he said, and swept his legs out of bed.

   


** ≋≋≋ **

  
 

Castiel couldn’t sleep either. Not because he was horny, but because there was a natural spasm response humans had to falling asleep in water, which Castiel hadn’t known until he tried it. The swan floatie was too deflated to be of any use. And leaning on the poolside was uncomfortable.

So he spent his time swimming in circles, feeling like a goldfish in a bowl so small it should’ve been outlawed.

He emerged from the depths, and coughed in surprise: Dean had entered the garage, looking harried. He took a length of rope and wound it between the door handles, effectively locking them in, or Sam out.

“Look,” he said, bowed legs striding up in his slippers, blue robe hanging loose from his shoulders. He was carrying a curved sword with a gold handle in one hand. “Cas. Here’s the deal. You got about two hours, maybe less, until you theoretically get back to normal.”

“Good,” Castiel said. “I can’t sleep like this.”

Dean palmed his hair back. “Yeah, well, maybe we’re not meant to be sleeping. We got enough time.”

“Enough time for what?”

Dean gulped. “Act it out with me. _Sweet Princess Asuka Meets the Tentacles of Pleasure_. Let’s go through it, like we’re acting in the movie. Just for fun, I’ll keep my underwear on, don’t gotta get weird about it.”

“Um.”

“I’m the princess,” Dean said firmly. “You’re Monsutā.”

Castiel parted his lips, then let them close. “All right?”

Dean grinned a little. “Okay. So. It starts in battle, right?” He stepped back a few paces, holding up his sword. He took a few testing swings, kiyahing at invisible enemies. “ _We will not let them win!_ ” he said in a soft, feminine voice. “ _To the death! Hyah!_ ” He plunged the sword into an attacker’s belly and stood back, wiping fake sweat from his head, surveying the battlefield.

After a long, dramatic pause, he murmured, “ _A great kingdom has fallen... And it is not the enemy’s._ ” He hung his head and sighed. “ _I have led us to defeat._ ”

Castiel watched, amazed Dean knew the script so well.

Dean ran a few paces along towards the Impala, and sat on her hood, primly, as if she were his throne. His robe spread across the Impala’s headlights. Something solid in his pocket hit the light, but he ignored it. “ _My beautiful ladies,_ ” Dean said to his invisible handmaidens, “ _The stories are true. I am the monster of the land._ ” Dean waggled his hand, and explained, “That bit’s kind of lost in translation, apparently it’s in reference to an older version of _Tentacles of Pleasure_ that had a backstory in the opening credits. I’ve been looking on Ebay but those versions go for literally a thousand dollars or up, so I never— Okay, sidetracked.” He cleared his throat and returned to his prim position, stroking his hair as if it were longer. “ _This crown is not fit for a ruler like me. I’m nothing but poison to this kingdom and its people._ ”

Castiel had guessed at how Dean might relate to the princess when they watched the movie, but his heart sank, now, because he heard in Dean’s voice how much the words meant to him. Princess Asuka never had that emotional inflection, at least not in the English dub they’d watched.

“And this,” Dean said, twirling a finger, “is this where her maids tell her about the pool in the forest, where the waters can cleanse emotional darkness from a person, help them come to terms with their dark subconscious and find answers, yadda yadda. _Tell me, my beautiful assistant, where I can find this pool. I must go there immediately_.”

Dean slipped off the car and paced slowly, taking careful steps across the concrete. He cut the forest vines with his sword, his lips pursed in a serious expression of determination.

“And then,” Dean sighed, “she finds the pool.” He opened his arms wide, gesturing to the ten-foot overground paddling pool, containing Castiel and a deflated swan. Dean waved a hand at the swan. “Lose that thing, Cas. It’s breaking the immersion.”

Castiel chuckled and pushed the swan out of the pool, apologising to it when it plopped onto the concrete.

“ _O, magic pool,_ ” Dean cried, falling to a crouch beside the pool, hands on the border. “ _Cleanse me of my sins, save me from myself and help me recover this land from the sorrow that has befallen it at my hands..._ ”

He wore such a beautiful expression, Castiel couldn’t look away. He’d never seen Dean so gentle and open, nor heard his voice so breathy. He was clearly not intending to be himself, but there was so much of himself in his words that Castiel helplessly overlooked the soft voice and the languid movements, seeing Dean at his most vulnerable, wishing in another’s voice for something he wished for too.

Dean peered out across the lagoon, at the rippling surface. “ _O, magic pool,_ ” he said again.

Castiel waited for the next line.

Dean went, “Psst!” He shot Castiel a glare. “That’s your cue, dude.”

“Oh! Oh...” Castiel ducked under the water, swam in a circle, then launched out in a roar of water, arms rising, a beastly snarl aching on his face. “ _Who dares disturb my peaceful waters? Who dares—_ ” Castiel looked upon Dean’s face, his eager eyes and little smile, and swam to him, caressing his jaw. “ _O, sweet girl._ ”

Dean sucked his lower lip. “Princess.”

“What?”

“It’s ‘O, sweet Princess’.”

“Oh. _O, sweet Princess_.”

Dean melted, a tiny gasp parting his lips. His eyes had darkened, his attention hungry on Castiel. “Yeah. I’m— I’m your Princess.”

Castiel didn’t remember that from the movie. “Um...”

Dean blinked in a panic, then rushed, “ _My name is Princess Asuka and I seek your help, monster of the deep._ ”

Castiel purred, caressing Dean’s jaw, getting close enough to breathe his air. He didn’t remember all the lines of the script as well as Dean did, but he remembered how Monsutā touched; always gentle, always with care for the innocent princess.

“ _Join me in my lagoon of love, Princess. I sense how greatly you crave the touch of darkness._ ” 

Dean started to pant. “Hm.” He licked his lips. “Heh.” His eyes rose to the lights hanging from the garage ceiling, or perhaps the clear blue sky.

“ _I can pleasure you the way you_ ache _for_ ,” Castiel recited against Dean’s blushing cheek. “ _Perhaps neither of us are monsters after all._ ”

Dean shut his eyes.

“Neither of us are,” Castiel said again, in his usual voice. He held Dean’s shoulder assuringly.

Dean swallowed. “You sure about that, Cas?”

Castiel smiled, meeting his eyes. “Get in and find out.”

Dean grinned, eyes darting away. It was a silly game, they both thought so, but Dean did as he was told, dropping his sword, shedding his robe, kicking off his slippers, different to the formal, methodological way Asuka undressed herself, but ending with the same result.

Dean hesitated on the band of his boxers, but decided to keep them on. “Not gonna get weird about it,” he reminded Castiel, but as he climbed into the pool, Castiel wondered if he was only reminding himself.

“Ooh, chilly,” Dean hissed, wading waist-deep in the water. His nipples were erect, hands skimming the water. He caught Castiel’s eyes and grinned.

“ _You are as sweet and beautiful as the whispers on the wind promised me,_ ” Castiel murmured beside Dean’s shoulder. “All these freckles...”

Dean giggled, curling in on himself a bit. “Caaaas,” he complained.

“You have an adorable laugh, Dean,” Castiel told him, looking up the inch between their heights, bristling his stubble with his fingertips. “Especially when you’re shy.”

“I don’t—” Dean grinned and shrugged bashfully. “Don’t usually laugh like that.”

“Well, I like it,” Castiel said, stroking Dean’s shoulder with his wet hand. Dean shivered, a flash of pleasure crossing his face. Castiel let his hand trail down Dean’s spine, and Dean moaned quietly, eyes shut, eyebrows up, apparently surprised by what he felt.

“ _I can help you,_ ” Castiel said, lowering his voice to Monsutā’s oily purr. “ _I can take your darkness if you allow me inside you. Will you let me help you?_ ”

“ _I’ve never let anyone help me,_ ” Dean said, eyes down to Castiel’s heart. “ _All my life I’ve gone without help, why should I change now? How could you change me?_ ”

“Because you want to change yourself,” Castiel realised.

Dean met his eyes, stunned.

“She wants to change her ways for the sake of her kingdom and her subjects, so she allows Monsutā to help her. She doesn’t want to feel like she’s poison any more. He didn’t cleanse her, she cleanses herself by wanting to change and taking action.”

Dean smiled. “Uh-huh.”

“But at the same time, it was Monsutā’s help that drives her to lead her kingdom to victory in the end. The act of accepting someone else’s support, and love, that was—” Castiel chuckled. “I understand why you love this movie, I really do.”

Dean grinned, head down, swaying in the water. His fingers touched Castiel’s stomach, then slipped to the soft border of pale and indigo blue.

Castiel returned his expression to neutral, and finally gave his proper reply: “ _You came here for change, Princess. You made your wish. Now let me grant it the best way I see fit._ ”

Dean trembled under Castiel’s hand. He seemed excited, nervous, knowing what was to come.

“ _I don’t even know you,_ ” Dean said softly. “ _How can I give myself to you?_ ”

“ _You know me,_ ” Castiel assured him, “ _for this pool only shows a reflection. I am your darkness. Embrace me; release me from the prison you made for yourself._ ”

Dean lowered his eyes, smiling. “Guess this is where it gets dirty, huh.”

“What do you want to do here, Dean?” Castiel asked softly. “Do you want me to touch you, or—”

“Just acting, right?” Dean flashed a tiny grin. “Over the clothes. We don’t really. I mean. Unless you wanted—”

“Over the clothes is fine,” Castiel said quickly. “But, um... I have to ask, you and I have never done anything like this together... Are you... sure about this?”

Dean obviously wasn’t, but he nodded.

“You’re not,” Castiel told him. “Do you want to stop now?”

Dean considered it, but then frowned. “We’re embracing our darkness, right? Paying attention to the difficult crap we try and push down all the time?”

“That does seem to be the underlying message of the movie, yes.”

Dean let out a breath through his nose, lower lip trembling once, until it steadied. He nodded. “I wanna keep goin’.”

“Good,” Castiel whispered, eyes lowered to Dean’s heart. “Me too. Are you ready?”

Dean nodded. “Uh-huh. _I agree to your terms, O beast._ ”

Castiel swept up and grabbed Dean tightly around the waist, making him cry out in shock and pleasure – real pleasure. Dean fought to control his urge to moan, his soft mewls turning to breaths in seconds. “Oh— Ouhhh, Cas, Cas, shit, shhhit, oh my God,” he whimpered, feeling a tentacle between his legs. “Oh my God. Oh my God.”

“ _Do you feel that, Princess?_ ”

Dean nodded, crying out. “Yeah! Yeah. Oh, hmmmm.” He bit hard on his lip, eyes half-closed, weak in Castiel’s arms although he gripped the side of the pool firmly. “ _I’m ready to be helped, beast._ ”

“ _Monsutā,_ ” Castiel said. “ _That’s my name. Call me Monsutā._ ”

“Cas,” Dean whispered, shivering as Castiel stroked a tentacle slowly against Dean’s taint. Dean gasped hard and threw back his head, strangling a moan before it could escape. They bobbed in the water, Dean searching for a rhythm, wanting more pressure.

Castiel wasn’t sure what to do; this wasn’t supposed to be sex. It was a game. But Dean was dark-eyed and desperate, his legs shaking, his weight shifting as if he were making love.

“Cas... Cas,” Dean breathed, a line pressed between his brows. “Auhhh...” A fragile expression fluttered across his face, lips shaping around an ‘O’. “F-Feels so good. So damn good.”

Castiel let the suckers on his tentacle pull past and pluck free from between Dean’s inner thighs.

Dean began to hump forward, smiling dazedly. “Uh... Ah... yeah... yeah...”

“ _Princess—_ ” Castiel tried to do Monsutā’s voice but it shattered and he could only whisper, “Princess...? Is this too much for you?”

Dean shook his head. “I’m good. I’m good, Cas, don’t stop.”

Castiel thrust his tentacle between Dean’s legs, another joining it, another sweeping behind Dean’s back to pull him closer.

“AUUh...” Dean wrapped his arms around Castiel’s neck, folding against his torso, forehead down on his shoulder. “Cas, I’m hard. I’m so fucking hard right now.”

“I thought you didn’t want to be ‘weird’ about it,” Castiel chuckled.

Dean grinned. “Can you ignore it? Pretend to fuck me. Like I’m Princess Asuka.”

“I can do that.”

“It’s not weird for you?”

“I don’t think it’s possible for anything to be weirder than this already is,” Castiel said. “So, no.” His hands grasped Dean’s waist without warning and turned him face-first against the edge of the pool, Dean yelping, Castiel coming up behind him to take hold of him eight different ways, pulling his bowed legs apart, two tentacles teasing Dean’s anus and taint through his soaked-through boxers.

“Cas!” Dean was shaking, grinning, breathing out through narrowed lips. “I— I mean, Monsutā! _Monsutā..._ ”

“Princess,” Castiel replied, caressing Dean’s freckled back, resting his nose on the knot at the top of his spine. “Oh, my love, my love.”

Dean shuddered, turning his head. “Breaking script?”

“ _Beautiful princess,_ ” Castiel said flatly, before rolling his eyes.

Dean stammered and stumbled over the next few lines, mostly cries of pleasure, but each one came out broken by his own voice, his lip-bites, his shaking breath. He pushed back on Castiel’s tentacles, wanting more-more-more.

“Cas—” Dean waved a hand under the water, trying to get a tentacle. Castiel gave him one, blushing when he realised which one he’d given. “Put.” Dean drew the tentacle to his nipples, holding it there until Castiel stroked. Castiel let out a soft sigh of expected delight: Dean’s nipple was pointy, and Castiel’s suckers slipped easily around it, back and forth, as if scratching an itch he didn’t know he had.

“God,” Dean grinned, head flopping down as the water around them became turbulent with their thrusts. “Wish I had boobs right now.”

“I like these,” Castiel assured Dean, sliding both hands to join his tentacle, holding Dean’s flat chest in both hands, swirling, rubbing, making Dean whimper. “I like your shape, Dean.”

“No bounce,” Dean breathed.

“I can make us bounce.” Castiel shot out four tentacles to the edges of the pool, snatching the barriers and using them to shake, pushing and pushing and pushing against Dean, as Dean held the barrier and pushed back, legs wide open, ass bared for Castiel, keening. The water turned choppy, sloshing out onto the concrete. Dean opened his mouth wide and _moaned_ , sobbing, nodding to tell Castiel he liked it.

Castiel moaned quietly, eyes on Dean’s neck, where there was a red flush, and a dozen pretty freckles. He wanted to kiss them all.

“Monsutāaaa,” Dean whispered, before shaking his head. “Cas. Cas.” He held Castiel’s tentacle over his heart and kept it there, stroking it. Castiel smiled, easing up close to Dean, wrapping his bare chest over Dean’s back, arms hugging all the way around his torso.

Castiel pressed a kiss to Dean’s shoulder. “Mm.”

“Ahh—” Dean squirmed, breathless and ravenous for more contact than he already had. “Cas, I want— I know we’re not meant to, I know we’re just friends, I know it’s just a stupid game, but I want—”

“What, what do you want, Dean?”

“Turn me around,” Dean begged, trying to twist. Castiel let him move, and embraced him again, thick ink-blue coils curling around Dean, holding him tight and close, so Dean’s erection pressed hot on Castiel’s abdomen, so Dean could wrap his arms around Castiel’s shoulders.

Dean droned a needy sound from deep in his chest, then shut his eyes and kissed Castiel open-mouthed on the lips, head turned.

Castiel sucked in a sharp breath, eyes wide open. He didn’t know how to respond.

“Mmh,” Dean purred, a hand combing through the hair at the nape of Castiel’s neck. “Mmm.” His kisses were tender and sweet and Castiel found himself melting into them, both him and Dean going still in the water.

They relaxed, eyes closed, holding each other and kissing. The only sound was the click of their lips.

Castiel felt Dean’s legs start to weaken, and he caught him, holding him up with tentacles and hands, sliding his hands up Dean’s slick back to cradle his jaw, turning his own head to kiss him again, again, smooching and sucking Dean’s lips, tongue licking the edge of his breath.

“Ahh...” Dean opened his eyes, dizzy. “Cas...?”

“Yeah.” Castiel kissed him again.

Dean gazed at Castiel with lust in his eyes, sucking his lower lip.

Castiel recognised it for what it was: a question.

He lifted a single tentacle to the leg of Dean’s boxers, teasing the soft tip up against Dean’s inner thigh. Dean shivered, a smile flashing across his face.

“Is this what you want?” Castiel asked deeply, kissing Dean’s cheek, jaw, chin... then, slowly, his lips.

Dean nodded, breaking the kiss.

Monsutā and Asuka never kissed in the movie. Not even once. Just by pressing his lips to Castiel, Dean had proven his intent to go beyond what the movie showed. Now, Dean and Castiel were not only embracing their darkness, but their light, too. Castiel felt the rush of joy inside him, brightness beaming under his skin with his heartbeat. All because Dean kissed him, and now wanted to go further.

There was no question any more. Dean didn’t want a tentacle monster, he wanted Castiel.

Dean kept his eyes locked to Castiel’s, the green rim around his pupils swallowed by black as Castiel forced that single tentacle further inside Dean’s underwear. It swelled under the fabric, sweeping up alongside Dean’s erection, and it hooked over the waistband of his boxers and pulled them down with expert dexterity.

Dean shivered, smiling fretfully, feeling himself exposed to the water, and to Castiel.

Castiel didn’t look down in case Dean was shy of being seen. He was as new to this as Castiel.

Carefully, Castiel traced Dean’s arousal with the suckered underside of one tentacle, another winding between Dean’s thick thighs, another stroking between his buttocks. He wound Dean’s waist in his tight grip, hoping to give him stability, and therefore comfort. The look in Dean’s eyes was tender, his hands uncertain on Castiel’s biceps – but one slick pull of a tentacle against his cock, and he spasmed into relaxation, mewling in such a vulnerable way that Castiel felt a rush of protectiveness, wanting Dean to be safe and warm and kissed all over – but at the same time, wanting to corrupt that hint of innocence with the power he had over him, wanting to strip away whatever barriers he had left, leaving him totally at Castiel’s mercy.

Castiel was the stronger beast, here. He could not walk, and he had no magic powers, but in the water, he was bold and confident, and Dean was but a plaything for him.

Dean sensed his vulnerability as acutely as Castiel did, while tangled in a knot of six-foot limbs. But he did nothing to gain back strength; he tensed no muscles, he gave no flicker of annoyance, he did nothing but lay his cheek on Castiel’s shoulder, hand open on his heart, seeking to give over control entirely.

Even Princess Asuka had never let her guard down this low.

Then again, her darkness was new to her. Dean had known of his hidden desires his whole life. Maybe, at last, he was ready to embrace them. He trusted Castiel like nobody else, and as he shut his eyes, biting his lip in pleasure, he awaited the moment Castiel would use that trust to do what he craved.

“Will you let me inside you?” Castiel whispered, lips on Dean’s water-damp forehead. “Will you accept me as I am?”

Dean opened his eyes, love in his gaze as he looked up. “Yeah.”

Castiel’s heart leapt. He wanted to do as he said, but there were practicalities that could not be handwaved the way they were in animation. “H— How do I—? I’ve never, I don’t actually know how—”

Dean grinned, kissing Castiel’s collarbone. “Pocket of my robe.”

Castiel rotated in the pool, peering over the side. One tentative tentacle loomed out of the pool, dripping, nudging the discarded robe until the pocket presented itself, and Castiel pulled out a bottle. “Lubricant,” he realised.

Dean wore a little smirk. “You, uh. Gotta get my ass outta the water to put some on. But it’s silicone-based so we’ll be good underwater.”

Castiel came to the understanding that Dean had planned for this eventuality all along, before he ever left his bedroom tonight. Perhaps he hadn’t known they’d get this far, but he had brought lubrication just in case...

Castiel lifted Dean’s body in the water, making him laugh as he turned him around, ass up.

“Easy, tiger, go easy,” Dean chuckled, hands on the pool edge as Castiel glooped a good amount of lubricant between his plump buttcheeks. As Castiel smoothed it all around the area with a tentacle tip, Dean gasped, legs twitching, breathy laughs escaping him. “Ooh!” He liked being prodded.

Castiel lowered the bottle to the ground with one tentacle, while his other tentacles wrapped Dean in a hug, face to face, bringing him close enough to kiss. Dean sighed, a ragdoll in Castiel’s human arms. He accepted kisses, and nosed forward for more whenever Castiel paused for air.

“C’mon,” Dean said, squirming back on a tentacle. “Get in me already.”

Castiel breathed out, preparing himself emotionally. To him, it didn’t seem such a big leap to go from kissing to penetration; they seemed like equally intimate and loving acts to him. But he knew Dean would see them as different things entirely, and to have Castiel inside him would change his perspective of their relationship forever.

But Princess Asuka sought change, even though she feared it. And, in this moment, so did Dean.

So Castiel slipped inside.

Dean’s expression shifted; his eyebrows rose and angled outwards; his eyes shut feather-light, showing the delicate red veins on his lids; his lips parted, widening around an ‘ah!’ that never came out audibly. His hands clutched Castiel’s biceps just beside his shoulders, shivers of pleasure trembling through his lower half. Castiel was close enough to him to feel the heat of pre-come emerging into the water from Dean’s cock, thick fluid drifting against Castiel’s skin.

Castiel was awed by Dean’s tightness, how he consciously clenched his hole and relaxed it, like he was trying to suck Castiel’s tentacle deeper. Castiel obliged, grinning in delight when he saw how the sensation affected Dean. He was crumbling, his toes and thighs and hands and arms tense while his neck went slack, head back, spine arching to make Castiel sink deeper.

“How do you like that?” Castiel asked, kissing Dean’s jaw, kiss, kiss, kiss. “Dean?”

Dean nodded, gasping. “‘S good. Auhhhh...”

“Can you feel all the suckers?” Castiel wondered.

Dean nodded. “Mm-hm.” He gasped. “Auhhcas! Cas. Cas.”

Was there anything of the game left, at this point? Or had Dean given himself over to wanting Castiel, truly, and not Monsutā?

“What are you thinking about, Princess?” Castiel whispered in Dean’s ear, as one tentacle played with Dean’s foreskin, circling it, sinking down in rings, then rubbing his thickened length a few times as Dean whimpered.

“Th-thh,” was all Dean could manage before groaning deeply, flopping forward to rest with his forehead against Castiel’s throat, hot breaths puffed down to his clavicle. “Ouaaah, Cas— CasCasCas, ah!”

He writhed in Castiel’s grip, fucking himself on a steady tentacle, making Castiel’s own composure shudder and shake; he started to moan, realising that he too enjoyed becoming vulnerable at Dean’s demands, given pleasure and sensation without taking it himself. Castiel’s tentacles loosened their grip on Dean in his shock, as he cried, “Dean— Deeeeeannnn...”

Dean laughed, taking the back of Castiel’s neck in both hands, planting a kiss on his cheek. Castiel felt him stand on the bottom of the pool, and, like Castiel had done for him, he grasped Castiel’s body in his arms, keeping him secure, as he rubbed his cock on the divide between Castiel’s navel and his octopus half.

“Dean,” Castiel breathed, hands shaking on Dean’s back. “Oh— OH!”

Dean had slipped a hand under Castiel’s tentacles, fingers finding his second mouth. Castiel kept it closed, sure he could accidentally bite Dean’s fingers off, but the human part of him gasped and squirmed in ecstasy as Dean realised along with Castiel that the soft underside of his body, the part without any suckers, was a _massively_ sensitive erogenous zone.

“So goddamn _smooth_ ,” Dean mused, grinning against Castiel’s cheek. “Feels like the top of a jello cup. You like that, Cas?”

Castiel nodded frantically. “Auhh— Ah! Dean! Dean! Oh, oh—”

Dean stroked, following the top arches where two tentacles met. Castiel felt the erectile tissue in the tentacle inside Dean start to pulse, and he whimpered, unable to speak. His eyes rolled back in his head, fingers clawing on Dean’s back.

“Yeeeah, you like that,” Dean confirmed, cocky, nuzzling Castiel’s ear. “You horny little monster.”

“Hmm— Hm!” Castiel dug his tentacle faster and deeper into Dean, thrusting it urgently, enjoying that Dean’s hands shook as they followed another arch on his sleeker underside.

“Can you come?” Dean asked Castiel. “Can your tentacle dick come inside me?”

Castiel chuckled, but nodded.

“‘Kay,” Dean grinned, eyes on the ceiling. “Gotta— Hhhf, mm. Gotta check that off my – my bucket list.”

Castiel held him closer and laughed against his neck, decorating him with kisses more often than breaths.

“Cas,” Dean spasmed, pausing what his hands were doing to Cas, to focus on what Cas was doing to _him_ : tentacle in, tentacle out, while another one teased the rim of Dean’s hole. Dean bowed forward, whining, sticking his ass out for more. He soon collapsed into Castiel’s arms, and Castiel held him, cradling him to his chest, kissing his cheek and his pouting lips, loving the little “Mm... mhm? Mmm,” sounds Dean made as Castiel fucked him slowly, gently, filling him as much as Dean’s body allowed. Dean lay a hand on his erection underwater, but barely stroked; he seemed content enough with what Castiel gave him.

Dean’s breath began to shudder, his hands moved to press on Castiel’s chest; he opened his mouth to murmur a pleased noise.

Castiel looked between his legs to see the indigo pulse of his tentacle, filling Dean’s hole, staying inside but thickening and shrinking as he urged his muscles towards Dean in waves. Fucking, fucking, making Dean wriggle; Dean always wanted more contact, more movement, more pressure. Even when he was silent, he was a demanding sex partner. But when he didn’t have what he wanted, he asked, or took it for himself; Castiel was grateful, since he didn’t really have the slightest clue what he was supposed to do without instruction.

With no cue to change his pattern, Castiel kept going, noticing how Dean’s breath shortened and came out unevenly, his temperature rose, his fingers tensing and relaxing on Castiel’s chest.

“Ah— Ahh—”

Dean’s lashes fluttered – and that was the last signal before he froze up entirely, crying out; Castiel noticed but didn’t look at the spurt of white that shot into the water, cock jumping as it threw a second wet spark out of the water. Castiel only watched Dean’s face, that shocked expression sinking to mirth, and satisfaction, biting his lip.

Dean opened his eyes and gazed at Castiel sweetly, reaching up to stroke his jaw.

Castiel grinned down at him, helping him to stand. Dean slipped on the pool base, dropping into the water with a splash – Castiel yelped, the fastest yank of his penis becoming more than he could handle in a split-second. It was only when he sank back into the water, feeling woozy, that he realised he’d climaxed.

Dean was laughing when Castiel became aware of his surroundings again. Dean had wrinkles by his eyes, and his mouth was stretched in a pleasant shape, teeth showing, head cocked quickly in an unexplainable but completely understandable gesture, mid-laugh. He was laughing and Castiel was starting to chuckle, taking Dean’s hand to pull himself upright.

“Do you know,” Castiel said, trying to catch his breath, as Dean waded up against him and draped him in a two-armed hug, “octopi die after mating. The males perish after a few months, and the females expire once her eggs have hatched.”

Dean scoffed, rolling his eyes. “Oh, sure,” he uttered. “Just like you, Cas, tellin’ me I might be putting you in mortal danger _after_ we do it. Nice pillow talk there, man. Real nice.”

“Luckily we don’t have long to wait until I’m human again,” Castiel said, kissing at the junction of Dean’s jaw and ear. “And then we can mate as much as we like without the danger of death.”

Dean slowed to a halt, halfway through a kiss. Castiel felt his eyelashes flicker against his cheek. “Uh-huh,” he said, but his tone said ‘wary’ not ‘agreement’.

“Thank you for this experience, Dean,” Castiel said, pulling back to smile at him, hands stroking his waist. “Princess.”

Dean’s tongue darted out to wet his lips, but he didn’t smile. “Mm-hm. Yeah. Was awesome.”

“Do you feel like your burdens have been lifted?” Castiel asked. “How was it to embrace your darkest secrets and face your fear?”

Dean’s eyes shifted away. “Yeah, it’s. It’s cool.” He shrugged loosely. “It’s. Y’know. Whatever.” He licked his lips again – still swollen – and then cleared his throat, taking a step back. “Thanks. Cas. For. For this.”

He stood and stared for a moment, but before Castiel could speak the reply on his tongue, he had to turn his head, watching Dean hop to the edge of the pool and launch himself over the barrier, splashing water onto the floor.

“I’mma go take a shower now, so.” Dean picked up his robe and donned it, tied around the waist. “See you later, I guess.”

“Dean...” Castiel bobbed to the edge, leaning out to take Dean’s arm. “Is something wrong?”

“Ah, no, no, I’m just. Feeling weird. Y’know. Because we said we wouldn’t get weird about it, and then we did, and it was a whole thing. And. You get it, right? Gotta. Go deal with that.” He saluted Castiel with one hand, backing away, lubricant in his pocket, sword in his hand. “Seriously, though, man – dream come true.” He grinned, clicking his fingers and pointing in Castiel’s direction. “Keep up the good work.”

He practically turned and ran, after that. He couldn’t get the rope undone from the doors fast enough. The door slammed back open when he left, as he left in such a rush.

Castiel felt a draft come into the garage from the bunker. It smelled like pie and cupcakes.

   


** ≋≋≋ **

  
 

“Dean?” Castiel fell naked against the bunker’s hallway tiles, body leaning fully on the wall. The lights were all on but nobody was around. “Saaam?”

A single echo of his voice came back to him through the halls. “Anyone? Please, I— I need—”

His legs were weak, shaking violently. “Dean—!”

He shut his eyes, exhausted. “Please...”

He slumped to the ground, one side of his bare ass flattened to the tiles, chilled and bruised by them. His legs splayed to one side, his torso held up by the wall.

A tumbling patter of feet came down the hall, and Castiel looked up in time to see Sam come sweeping around the corner, messy-haired, wearing a grey V-neck and sweatpants.

“Cas!” Sam ran to Castiel’s side, hands darting to his arms and chest but not touching him, as he was very naked. “Are you okay? You’ve got your legs back—”

“Oh, I hadn’t noticed,” Castiel snarked, frowning as he closed his eyes again, hair ruffled against the wall. “I must’ve _crawled_ here without _realising_.”

Sam huffed out a laugh. “Do you want me to get you to your room?”

“I need the bathroom,” Castiel said. “And a shower. And clothes. And water. And food. And then I need to see Dean.”

Sam raised his eyebrows, but he took Castiel by the arms and helped him up, slinging one floppy arm over his shoulders, starting to walk towards the bunker’s biggest bathroom, with five showerheads lined up on one wall like a locker room.

“Did Dean tell you?” Castiel asked.

“Tell me what?”

Castiel felt a sag of disappointment in his chest. “What happened between uh... Nothing. Never mind. I’m delirious.”

“Yeah, about that. Don’t you think you ought to sleep? It’s two-thirty in the morning, and you didn’t sleep last night, either. Do all the other stuff – bathroom, food, shower – but talk to Dean when you’ve rested.”

“No, it has to be now,” Castiel said. “Especially because—”

“What?” Sam turned the corner, helping Castiel into the bathroom, walking him towards a toilet cubicle.

“Because,” Castiel said, “when I sleep, I intend to sleep in his bed. And he really ought to know about it before I do so.”

Sam didn’t say anything to that. He simply processed, and helped Castiel take his own weight, patiently waiting outside the cubicle until Castiel was done.

   


** ≋≋≋ **

  
 

The bedside light was on. Dean lay flat on his bed in fresh underwear and a t-shirt, over the blankets, eyes closed, both elbows in the air, palms over his face. His nose poked between his hands, and with every exhale, he groaned a little, in frustration with himself, but plagued by the knowledge that his fears were justified, and he had been right to step back.

The thing was, the reason he never made a move on Cas before tonight was in fact two reasons.

Reason one: Dean was resistant to fixing what ain’t broke, which included being open with people when he didn’t need to be, and feeling vulnerable when they had private information on him that he was still busy enjoying for himself. Sam didn’t need to know there was a dick-shaped vibrator under Dean’s mattress, just as Cas didn’t need to know Dean was so in love with him that he hadn’t slept with anyone else in years because it felt wrong. Dean was afraid to have that information shared, because then his dirty little secrets wouldn’t belong to him any more. He’d never had any intention of voluntarily sharing those facts.

Reason two: Dean knew that, if – _if_ – in the eventuality that things did come to a head with Cas, and they accidentally kissed in the heat of the moment after a hunt, or were locked in a magic room and were forced to express their feelings in order to get out, or Cas walked in on Dean while he was having some private vibrator time – in such a case, should they somehow end up in a relationship, Dean would go crazy just from worry.

He worried about Cas enough already, but he had an inkling that if things stepped up a notch, his concern about his best friend would skyrocket. He already couldn’t deal with not seeing him for a week at a time, or not hearing from him in a couple nights. He thought about him all the time. If he got over himself enough to say something stupid like ‘I love you’, how the _hell_ was he meant to cope with how it would feel to be apart from him, or know he was in danger? Or to _lose_ him?

Dean loved Sam with every bit of his heart, and he would and _had_ died for his little brother, as he would for Charlie or Jack or his mom, but there was just something about Cas that lent itself to far more subtle but long-term acts of selflessness. Dean _wanted_ his every action to revolve around the guy. He wanted to do what Cas said, and follow his lead, and hunt him down in the afterlife just to kick his ass for leaving Dean behind.

Dean wanted to be chill about all this. Loving his guardian angel wasn’t so bad, right? But he loved him too much. He knew it was too much. He had the codependent habits almost kicked with Sam, but the tools he’d learned along the way with his brother couldn’t quite be applied to Cas.

Why?

Because Cas was different. Because Dean’s love and protective urge was justified. Cas died almost as much as Dean and sometimes it took him _way_ too long to come back. Dean was _allowed_ to be worried.

John always left. As a kid, Dean was shown love by being left alone, uncared for. He knew it would be all-too-easy to overcompensate with Sam, with Cas, with Jack, with anyone, and become overbearing and overprotective and never leave anyone he loved alone in case they needed him, or hurt themselves.

And that was why he had to step back from Cas. Dean knew when ‘too much’ was coming, and the moment Cas mentioned that octopi died after mating, that grasping, violent urge rose up in his chest, wanting to punch the entire conjoined concepts of loss and death. Up until that moment Dean had been under the vague impression that octopi were biologically immortal, like turtles, or jellyfish, or like angels were supposed to be.

Dean kind of wanted to cry. How did octopi even deal with that? Wanting to breed, make little octopus babies, and then scooting away to die? Those poor tiny babies, growing up without parents.

So that was what Dean was doing. Groaning, hands over his eyes, because octopi weren’t immortal and because he loved Cas way too much.

That was what Dean was still doing when Sam knocked on the door.

Dean sat up, bleary-eyed. “Uh?”

Sam stood by the door, water spray from the shower all the way down one side of his t-shirt. “Special delivery,” he said.

Dean squinted at the clock. “Dude, it’s three in the morning, what—”

“Dean.” Castiel walked in. Slowly. Weakly, eyes drooping, half-closed, one hand slapping to Sam’s to keep him upright. “I need to talk to you.”

“What— Now? Can’t it wai—”

“No,” Castiel was so determined it was clearly pointless to argue. He went around the bed, hands on the frame, the blanket, the nightstand. He sat on the empty side – the side Dean secretly saved for him – and collapsed back onto the bed, head on the pillow, bare feet on the blanket, sighing, eyes shut.

“You okay?” Dean asked quietly, propped up on one elbow. He looked at Cas in concern, a familiar tingle of worry in his chest.

“No,” Castiel said. He lifted his head. “You can go now, thank you, Sam.”

Sam pressed a friendly smile between his lips. “‘Night.”

Dean only raised his fingers in a half-wave before turning back to Cas, now the door was shut. “Cas, what’s wrong? I mean, awesome, you got your legs back. But shouldn’t you sleep?”

“How dare you,” Castiel said grumpily.

“What?”

“How dare you up and leave me exhausted in a pool with only an hour until I change back. I had to crawl, Dean.” He snorted. “I’m thoroughly peeved at you.”

Dean couldn’t help grinning at his choice of words. He sobered, though, and said, sincerely, “Sorry. I know that was a dick move. Kind of ironic, too,” he thumbed his forehead in shame, “given why I took off.”

“You had to ‘process’,” Castiel said with finger quotes, even though it wasn’t an exact quote, but it was close enough. “We had sex, Dean, and we _kissed_ , and then you ran away. Why? What was there to process that we couldn’t process together? What made you so sure it wasn’t as rattling a change for me as it was for you? My body is _exhausted_ , Dean, and my emotions are fragile, and— And—” His eyes watered, gleaming gold in the light. He sniffed. “And I didn’t want you to go, but you left, and I didn’t _want_ to be alone—”

“Cas,” Dean sobbed, wrapping his arms around Castiel’s chest, eyes shut, forehead on his heart. “I’m sorry. I’m sorry, I suck, I know. Shit, why are you even _here_ , you should’ve just asked Sam to come in here and punch my goddamn lights out.”

“Pff,” Castiel said, smiling through his tears. “And let _you_ get some sleep? Please.”

Dean snuffled a sad laugh, feeling a tear dribble off his nose and into Castiel’s t-shirt, a Pearl Jam one Dean recognised from when he ironed Sam’s stuff last.

“I’m sorry,” Dean said again.

“Tell me why.”

Dean sucked his tongue, eyes drifting to a dark corner of his bedroom, while his cheek remained on Castiel’s breathing chest. “It ain’t gonna surprise you.”

“Try me.”

Dean pouted. “Octopuses dying when they have babies.”

Castiel’s chest jumped once as he laughed in silence. His hand came to rest in Dean’s hair, scrunching it.

“Din’t want you to die, okay,” Dean mumbled, eyes shut, rubbing his nose into Castiel’s shirt. “I hate when you’re not here. I think about you – literally _all_ the time. It ain’t healthy, Cas. But you could guess, kinda, what that’s like, right? Lh— Loving? someone? A-And them being the most awesome kindest sweetest most loyal and beautiful goddamn thing that ever roamed this garbage Earth with its stupid unimmortal octopuses. And feelin’ so lucky whenever they even hint that they like you, or do something for you, ‘cause you’re such a trashbag and a murdery self-hatin’ monster who can’t do anything right, and they’re – they’re everything to you.”

Castiel only stroked Dean’s hair again, warm fingers through warm hair.

It went silent for a while, then Castiel sighed, and said, “I know exactly what that’s like.”

Dean lifted his face, chin digging into Castiel’s sternum, and he looked softly up at Castiel, past his stubbled chin wrinkles and lips and cheekbone bumps, into those blue lagoons of love he called eyes.

“Yeah,” Dean whispered. “Guess you do know.”

Castiel smiled lopsidedly, pushing Dean off his chest, rolling towards him, so they lay facing each other, each on their own side of the bed, close enough to feel the heat of each other’s breath.

“Dean, I have to ask,” Castiel said, eyes lowering. “Are you still attracted to me? With legs instead of tentacles?”

Dean laughed, rolling onto his back so he wouldn’t deafen Castiel. He patted his stomach, legs curled up, then rolled back to Castiel and kissed him, still chuckling, fingers under his chin. “Yeah.”

Castiel gave a small sigh of relief. “Good.”

“Guess we’re both too tired to prove it right now,” Dean murmured, taking Castiel’s hand and kissing it. “Some other time?”

Castiel snuggled closer, shoving one hairy thigh between Dean’s slimmer, less hairy thighs. Castiel wrenched Dean into a hug, and said, firmly, “We don’t need sex to prove anything.”

“We don’t?”

Castiel kissed Dean on the lips, pushing and sucking and slipping his tongue over the tender inseam of Dean’s mouth, making him shudder. “No,” Castiel said. “But I think, having done it earlier, it did prove one thing.”

“Oh yeah? What’ss’at?” Dean smiled, nuzzling Castiel’s face, loving how minty he smelled, and how forcefully he cuddled.

“ _The ritual is complete. Perhaps you have realised by now, O sweet Princess, you will never be free of darkness,_ ” Castiel said softly, stroking Dean’s cheek, holding his gaze. “ _Now you have met me, you will carry me with you, to your kingdom, to your subjects. You took me inside you willingly, and in return I give you this: I will help you rise to victory. I will help you win your battles. For this is the truth you came here to seek: failure and remorse are the greatest tools you have for improvement and renewal. I, as your darkness confronted and embraced, have become your greatest weapon. You will live a different life, henceforth. Go from this place, and I will follow you wherever you may lead._ ”

Dean shut his eyes, fingers stretching between Castiel’s.

Castiel kissed Dean’s eyelids, left, then right. He lay as close to him as possible, letting go of a slow, measured breath. “ _The most wonderful people, Princess, were once unwitting monsters. And like any monster, once they open themselves to change, and are treated with kindness, and understanding, and patience, even a raging behemoth can eventually be tamed._ ”

Castiel pressed his foot against Dean’s ankle, reminding him of what had been returned to them.

Monsutā stepped from the lagoon and onto the shore, transformed from a beast to a man, a ready companion for Asuka. As they embraced before a marmalade sunset, silhouettes touching temple-to-temple, they faded into one another, the man disappearing with a spark into Asuka’s wide eyes.

She returned to the castle, her sword in one hand, a monstera leaf from the forest in the other. She lay down her sword in the grass, planted the leaf in the castle gardens, and then called to her handmaiden to dictate a message: “ _Order a summit with the rulers of the neighbouring kingdoms. I wish to bring peace not only to this kingdom, but all those that surround it. I believe... we may tame a few monsters yet._ ”

Castiel fell asleep in Dean’s arms, as Dean fell asleep in Castiel’s.

Dean snored with a little monster grumble every time he breathed out. He dreamed of nothing, because he knew he was already living the best dream imaginable.

Castiel dreamed of nothing, because his shadow was there, inside him, and he feared only solitude, a time without Dean, or family, love, or understanding of humanity. He feared going back to where he came from, losing everything he’d gained.

But there was peace in it, there was peace in the nothingness. Because there was always awareness that when he woke, he was loved. Dean would never leave him alone, not really. Sometimes he worried too much, but Castiel adored that. He needed that.

They could both work on worrying less. Trusting more. Taming that ridiculous, yet completely justified beast they shared as a pet.

But a beast like that?

That was a monster they could take down together.

 

**{ the end } ******

**  
**  
****  
  


   


**Author's Note:**

> ≋ [reblog fic (text)](https://almaasi.tumblr.com/post/183976608425/dean-and-castiels-lagoon-of-love)  
> ≋ [reblog art](https://almaasi.tumblr.com/post/183978363625/heres-a-cropped-version-of-my-art-for-my-125k)
> 
>  
> 
> Don't be TENTA-tive, SUCKER right up to comment box and gimme some INK.  
> (Translation: Tell me what you thought? Especially if tentacles aren't your thing, I'm very curious to know if this hit the mark.)
> 
> I have more highly-requested kink fics and the CUTEST fluff fics ready to post weekly, so [**subscribe**](https://archiveofourown.org/users/almaasi/) (on my user page, NOT on this page) so you don't miss them~!! ♥
> 
> Elmie x


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